1. Field of the Invention
The present invention relates to safety device of elevator and more particularly to a backup power device being automatically or manually operable in case of the failure of the elevator.
2. Description of Related Art
Conventionally, the speed of an elevator motor is regulated by a frequency changer circuit. Also, a car safety device is required to install in the elevator as a backup power device in case of the failure of the elevator (e.g., particularly one having a motor regulated by a frequency changer circuit). Unfortunately, the car still may fall freely if the car safety device also breakdowns in case of the failure of the elevator. Hence, a need for improvement exists.